An excellent Mexican pyrrhotite, truly a cut above the usual.  This one has a great luster, is entirely damage free, and displays the elongated form characteristic of Mexican pyrrhotites.  While piece likely dates to the 1970's or early 80's, it has an old collection label stating that it was purchased at the 1988 Denver Show.  Today most of the pyrrhotite on the market comes from Dal'Negorsk, Russia-- these Mexican pieces came out 30-40 years ago.